Treatment of sulfid and complex ores.



No. 799,696. PATENTED SEPT. 19, 1905. G. H. WARD.

TREATMENT OF SULFID AND COMPLEX ORES. APPLICATION IILED 001'. 2a, 1901.

4 sums-sum 1.

PATENTED SEPT. 19, 1905.

G. H. WARD. TREATMENT OF SULFID AND COMPLEX ORES.

APPLICATION FILED OUT. 28, 1901.

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WWW. /M 2% 1M, 5% Gym No. 799,696. PATENTED SEPT. 19, 1905.

0. H. WARD.

; TREATMENT OF SULPID AND COMPLEX ORES.

APPLICATION FILED DOT-28, 1901.

4 SHEETS-SHEET 3.

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No. 799,696. PATENTED SEPT. 19, 1905 4 G. H. WARD.

TREATMENT OF SULFID AND COMPLEX ORES.

APPLICATION FILED now. 28, 1901.

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TREATMENT OF SULFID AN D COMPLEX ORES.

Specification of Letters Patent.

Patented Sept. 19, 1905.

Application filed October 28, 1901. Serial No. 30,364.

To all whom it may concern.-

Be it known that I, CHARLES HARRISON WARD, metallurgist, a citizen ofthe United States of America, residing in the city of Sydney, in theState of New South Wales, Australia, have invented a new and useful Improvement in the Treatment of Sulfid and Complex Ores, of which thefollowing is a specification. My invention relates to a roasting processfor the treatment of sulfid and complex ores, and has for its object theconversion of the metals and metallic compounds therein to oxide,sulfates, or chlorids.

I My said process is conducted in a double fur-' nace which is sodevised that the gases produced in the one part of it are introducedinto the other part of it and so as that during treatment in the firstpart the ore will move in opposition to the flow of .gases passingthrough that part and in the other part of which it will becomegradually cooler while moving in the same direction and with the gasespassing therethrough. In the first part of the furnace the metals aredelivered in the form of sulfates and oxids, sometimes accompanied by asmall percentage of undecomposed sulfids, and the sulfating is completedor chloridizing effectedin the second part of the furnace. V-Vhen oredeficient in sulfurets is under treatment,sulfur in the form of pyritesis added to it before treatment is commenced. The resultingproducts'obtained in the second part of the furnace are in this casesimilar to those which areobtained when s'ul'fid ores are treated. Theroasting of the ore in the first part of the furnace qualifies it forthe chloridizing or sulfating processes which take place in the secondpart thereof. In the second part of the furnace the conversion tosulfates is continued and completed by means of water, air, and thegases from the first furnace. For the production of chlorids it isnecessary to add a reagent liberating chlorin during the process, commonsalt (chlorid of sodium) being used. It is mixed with the ore before itis introduced in the second part of the furnace. The chloridizing of theore is efi'ected for the most part in the second part of the furnace,where the reaction is assisted by the presence of water, which isintroduced, preferably, in the form of steam at and near the head ofthat part of the furnace. Where the object is to chloridize, thetemperature is gradually diminished in the second part of the furnaceafter the chloridizing reaction takes place in order to guard againstdechloridization, which is apt to occur if the temperature at whichchloridization has taken place is raised. Reduction of temperature isobtained by the introduction of steam or air into the furnace, thoughusually both steam and air are introduced. To chloridize, salt isintroduced with the ore on its entry into the second part of thefurnace, and steam is also introduced at this point. Salt in smallquantities may be mixed with the ore before its introduction into thefirst part of the furnace. When the ore contains lead sulfid, saltshould be used very sparingly or not at all until the ore hasbeendesulfurized, as'it is very liable to clog if chloridization occurs atthe same stage as desulfurization. At or .somewhere below the entranceto the second part of the furnace the chloridizing-point is reached, andthence to the delivery end of. that part of the furnace the temperatureis gradually diminished. The chloridized ore is finally treated in theusual way for the extraction of the metals therefrom.

Very considerable difiiculty is experienced in the chloridizing ofantimonial ores; but these ores are susceptible of very successfultreatment by my process, as the antimonial chlorid is preserved by thelow temperature of the furnace below the zone in which it is produced,practically no loss being sustained when the furnace is combined withadequate means for precipitating as chlorid and oxychlorid the antimonywhich comes over in the fume.

In carrying out my invention I may use double furnaces of various typesso long as the construction is such that the roasted ore may be conveyedreadily from the delivery end of the first part of the furnace to themouth of the second part of it and so that the gases from the first partof the furnace can be led into the mouth of the second part of thefurnace and pass through it in the same direction as and in company withthe ore under treatment therein. I may use two vertical furnaces side byside, this being the form which I prefer, or I may use a vertical and ahorizontal furnace, or I may use two horizontal furnaces. In. every casein the first part of the furnace the gases pass in the directionopposite to that taken by the ore. For instance, if the furnace isvertical and the powdered ore is showered down through it the gases aremade to ascend up through the descending shower of ore. In the secondpart of the furnace the gases traverse the furnace in the same directionas and with the ore,

IIO

intermingling during their passage therethrough with the water and airwhich are admitted for the purpose of assisting in the reactions whichoccurand also for the purpose of reducing the temperature after thesereactions have occurred.

The annexed drawings illustrate in a diagrammatic form severalconstructions of furnace adapted for carrying out my process; but Iwould have it understood that the fur nace may be modified extensivelyin form so long as it operates as hereinbefore described.

Figure 1 indicates the constructionof a fur= nace of the double-shaftvertical type, which is the one I prefer; Fig.2, a furnace of the doublehorizontal cylinder type;.F- ig.. 3,.afur1 nace of the vertical shaftand horizontalcyh inder type; Fig.4, a plan view of an -al-ter nativeform of a'furnaoe of the double hori zontal cylinder type. Fig. 5iudicatesia fur: nace of the vertical type with four shafts. Fig. 6 is adetail viewillustrating the means for controlling the air openings inacylin= drical type of furnace.

I In each of the viewsthe fire-gases for start=.

- chamber D can pass over the top of the septum F into the chamber E.The raw ore in powdered form enters through the hopper Gr, whence itpasses down over the. staggered hearth-plates H, falling at the footinto a hop per-bottom K, whence it is conveyed by suitable conveyermechanism or to the hopper L, feeding the second part E of the furnace.it passes down through this part of the furnace, also over the staggeredhearth plates H, and is taken out by a door M at the foot thereof. Thegases, fumes, and matters suspended therein are carried over through thetunnel N and are washed in the, usual way before be ing set free. 0represents gas=take-ofi trunks for leading furnace-gases out of thefirst part D of the furnace. Gas is drawn off through these trunk-s whenit is desired to cool the middle part of the first furnacevchamber D. Inthis case the main desulfurizing occurs at and near the top of thechamber D, while it is completed at the foot of the same. chamber. Bothparts of the furnace are fitted with air supply pipes P and steam orwater. supply pipes Q. The same letters. of referenceindicate.corresponding parts in Fig. 5, in which, as will be hereinafter fullydescribed, the, operations which take place in the chamber E in Fig. 1are prolonged and carried out in the chambers marked E, S, and'T in Fig.5. When this construction of furnace is used, the courses followed bythe gases and the ore being roasted are indicated, respectively, by

the arrows B and C.

Referring to Fig. 2, A is the fireplace, D the first part of thefurnace, and E its second part, both these parts being barrels formed ofa number of ring-sections of progressivelyincreased diameters, theflanges d e of which are apertured, as indicated in Fig. 6,.to formair-inlets and fitted with closures p of convenient form, whereby thelair-supply may be controlled. Vrepresents steam-supply pipes. I prefer,however, to support the barrels so they may be rotated by means ofsuitable mechanism, such as indicated at f. The raw ore inpowdered formenters by the hopper G and passes downward through the cylinder D andinto the collecting=box F, whence it passes through the scupper and isconveyed by conveyer mechanism m thence to the. hopper L, which feedsthe cylinder E. The gases which have passed through the cylinder D inanopposite direction to the ore stufiare carried through the end box Zinto the barrel E, which they traverse with and in the same direction asthe ore until they reach the'end box N, from which the fumes are takenoff by a trunk O and from which the treatedore is extracted through adoor M.

Referring to Fig.3,it will be seen that the first partfof the furnace Dis of the stack type, similar in form to the first part of the furnaceshown in Fig. 1. The gas is, however, taken off at the top through atrunk Q, by which it is conveyed to the end box R of the second part ofthe furnace E The ore treated in the chamber D passes out of the footthereof, through the hopper K and con- "veyer-trunk Y into the furnace Eand after treatment therein is taken out by the door M the fumes beingcarried away by the trunk- U for furthertreatment, as before described.Draft is maintained in the furnace by any suitable. means, such as by anordinary chimney-stack.

The construction of furnace shown in Fig. 4 differs from that shown inFig. 2 in that the gas instead of passing directly from the firstpartqor chamber D into the second part E of the furnace is conveyedbetween these two parts through a trunk Z while the ore is carried by anelevator m directly from the delivery end of the first part D 'of thefurnace into the mouth of the second part E thereof.

When a non-rotating furnace, such as is shown in Fig. l, is used, theair and steam pipes are led directly through the sides of the samewherever it is required to introduce air orsteam; but in the case of arotating furnace, as shown in Figs. 2 and 3 and 4 steam is ad mittedwhen necessary into the-mouths of both parts thereof, while air isadmitted through apertures in the flanges by which the sections areunited. In all cases the supply of air and steam is completely undercontrol, so that the same may be admitted whenever and wherever desiredin the precise quantities required in each particular case to producethe most advantageous results. It is usually more convenient to usesteam than water; but water introduced as a spray or otherwise may beused instead of steam.

In the several figures of drawings already described and in thedescription ofthe process preceding the same my furnace is referred toas a two-part furnace"; but, as indicated in Fig. 5, the second part ofthe furnace may be made in three or more chambers or sections if it bejudged desirable to subject the roasted ore to a longer or more gradualtreatment therein than can be conveniently eflected in one chamber. Whenthe furnace is made in three or more sections, the cooling down of theore and gases by the introduction of an excess of air is best effectedin the third and subsequent chambers, the second chamber being cooledonly to the extent which is incidental by the introduction of steam andair used to produce the required reactions.

The temperature of the ore when in the mouth of the second part of thefurnace must be at or above the chloridizing-point when the ore is to bechloridized. It must be sufliciently high to insure thorough sulfatingwhen the ore is to be sulfated. either case the gases shall accompanythe ore, moving in the same direction with-it through the second part ofthe furnace. All the ore and all the gases must pass through the hottestzone in the second part of the furnace and thereafter become graduallycooler before passing out at the end thereof. Reduction of temperatureis necessary in the lower portion of the second part of the furnace inorder to prevent the occurrence of reactions destructive of compoundsformed in the zone above it. Gradual reduction is not essential for thispurpose; but inasmuch as immediate reduction is not practicable andwould not be productive of any advantage and as it is desirable to bringdown the temperature to a relatively low point with a view to thefurther treatment of the ore and gases air is introduced at-a number ofpoints in the second part of the furnace, a gradual reduction oftemperature being thus effected.

What I claim as my invention, and desire to secure by Letters Patent, is

1. The herein-described process of roasting ores in the'presence ofheated gases, which consists in first passing the ore through a currentof such gases in a direction opposite to the flow of the gases, andsubsequently causing the ore and the current of gases to move togetherin the same direction, substantially as set forth.

2. The herein-described process of roasting It is essential that in oresin the presence of heated gases, which consists 1n first passing the orethrough a current of such gases in a direction opposite to the flowthereof, and subsequently causing the ore and the current of gases tomove together in the same direction, and reducing the temperature of theheated gases as they and the ore are moved together in the samedirection, substantially as set forth.

3. The treatment of ores of the kind described, which consists inroasting the ores in the presence of air by means of a current of heatedgases moving in a direction opposite to that in which the ore is moving,and subsequently causing the gases which result from such roasting tomove along with and in the same direction as the ore. the temperature ofthe gases being reduced while moving in the same direction as the ore,substantially as set forth.

4. In the treatment of ores of the kind described, the herein-describedprocess, which consists in roasting the same in the presence of air bymeans of hot gases moving in a direction opposite to that of themovement of the ore, then adding to the ore a substance containingchlorin, and then treating the ore with the chlorin bearing substanceadded with the gases resulting from the first step of the process, thetemperature of the gases during this last step being reduced,substantially as set forth.

- 5. The herein-described process of treating ores containing sulfur,which consists first in roasting the same by means of hot gases movingin a direction opposite to that in which the ore moves, then causing thesaid ore and the gases obtained from the first step of the process tocommingle and move together in the same direction, and graduallyreducing the temperature during such second step of the process by theintroduction of a cooling medium such as air and water, substantially asset forth.

6. The herein-described process of treating ores containing sulfur whichconsists in roasting the same, with access of air and water, by means ofhot gases moving in a direction opposite to that of the movement of theore,

then adding to the roasted ore a substance containing chlorin, thensubjecting such mix ture to the gases obtained from the first step ofthe process, and causing them and the ore to move together in the samedirection, and while so moving reducing their temperature by theintroduction of acooling medium, substantially as set forth.

7 The herein-described process of treating ores containing sulfur, whichconsists of the following steps: first, in raising the temperature ofthe crushed ore to a degree suflicient to cause the decomposition ofsulfids by means of a current of hot gases moving in a directionopposite to the movement of the ore; secondly, adding sodium chlorid to.the ore so gases,the herein-described process, which consists inpassing the crushed ore through a current of hot gases moving in adirection oppo- 1 site to that in which the ore moves, whereby thetemperature of the ore is gradually raised 5 to the desired degree, andthen causing the ore and hot gases to move together in the samedirection While their temperature is lowered, substantially as setforth.

In testimony whereof I have hereunto set my hand in presence of twosubscribing Witnesses.

CHARLES H. WARD.

Witnesses:

W. I. SPRUSON, W. I. DAVIS.

